(1) Technical Field
This invention pertains to locking systems useful to releasably position well flow control devices in a flow conduit in a well. The present invention particularly pertains to a lock mandrel carrying a flow control, which is oriented on lowering into a compatible landing nipple and rotated by the running tool to seal metal to metal and lock in the landing nipple.
(2) Background Information
Significant and very commercially successful prior locking systems are disclosed in U.S. Pat. Nos. 2,673,614 to Ira A. Miller and 3,208,531 to Jack W. Tamplen. In both prior systems, the running tool moves the lock mandrel downwardly into sealing and locking engagement with a compatible landing nipple in a well flow conduit. Both prior systems utilized resilient material for sealing which often deteriorates rapidly in high temperature and pressure environments in deep well conduits.